A polariton filter turns ordinary laser light into quantum light

An international team of researchers led out of Macquarie University has demonstrated a new approach for converting ordinary laser light into genuine quantum light.

Their approach uses nanometre-thick films made of gallium arsenide, which is a semiconductor material widely used in solar cells. They sandwich the thin films between two mirrors to manipulate the incoming photons.

Photons - Pairs - Semiconductor - Particles - Polaritons

The photons interact with electron-hole pairs in the semiconductor, forming new chimeric particles called polaritons that carry properties from both the photons and the electron-hole pairs. The polaritons decay after a few picoseconds, and the photons they release exhibit distinct quantum signatures.

The teams' research was published overnight in the journal Nature Materials.

Signatures - Moment - Work - Avenue - Photons

While these quantum signatures are weak at the moment, the work opens up a new avenue for producing single photons on demand.

"The ability to produce single photons on demand is hugely important for future applications in quantum communication and optical quantum information processing," says Associate Professor Thomas Volz from the Department of Physics and Astronomy and the senior author on the paper. "Think unbreakable encryption, super-fast computers, more efficient computer chips or even optical transistors with minimal power consumption."